1. Field of the Invention
The present invention relates to a magnet switch for starter for supplying a battery electric current to a starter motor. More particularly, the present invention relates to an improved switch contact of a magnet switch for starter.
2. Related Art
In a magnet switch for starter, a movable contact is moved with a plunger when an exciting coil is turned on, and the movable contact contacts a fixed contact so that a battery electric current is supplied to a starter motor via the movable contact and the fixed contact.
When the movable contact contacts the fixed contact, the movable contact is likely to bounce against the fixed contact due to the collision impact of the movable contact with speed, contact abrasion caused by the large electric current sparks progresses. Those are negative factors against the recent demand for the long-life durability of a starter.
For solving this problem, one countermeasure is proposed in Japanese Utility Model Laid-open Publication No. 61-13446. In this conventional art, an elastically deformable contact plate, which is electrically connected to a fixed contact, is provided on the fixed contact at the side facing a movable contact in order to prevent the bounce of the movable contact when the movable contact is brought into contact with the contact plate.
According to the conventional art, because an electric power is supplied to the movable contact from the fixed contact via the elastic contact plate, degradation in performance is developed because of the voltage drop due to the addition of a contact portion. Further, the addition of the contact plate raises the cost of the magnet switch due to processing and assembling of the contact plate.